How to Identify and Treat Common Tree Diseases in Houston?
Trees are one of the most valuable parts of any property in Texas. They provide shade from the Texas sun, add beauty to your yard, improve air quality and even increase your home’s value. But trees can get sick just like people and pets.
In Houston, the combination of hot summers, high humidity and heavy clay soil makes trees more vulnerable to certain diseases. These diseases can spread quickly and cause permanent damage if not treated in time even leading to tree death.
The good news is that most tree diseases can be managed or prevented if you know what to look for. In this guide, The Tree Pros Houston explains the most common tree diseases in the Houston area, their warning signs and the steps you can take to protect your trees.
1. Oak Wilt
What it is:
Oak Wilt is one of the most destructive tree diseases in Houston. Caused by a fungus, it spreads through root connections underground and by beetles above ground. Red oaks are the most at risk but live oaks can also suffer.
How to spot it:
- Leaves turn brown starting from the edges and moving inward
- Leaves fall off in the middle of spring or summer instead of fall
- Entire sections of the tree die suddenly
Why it’s dangerous:
Oak Wilt can kill a healthy tree in just a few weeks. It also spreads quickly to nearby oaks which creates large patches of dead trees.
Treatment & Prevention:
- Contact a certified arborist immediately—time is critical
- Fungicide injections may help slow down the disease
- Avoid pruning oaks in spring and early summer to reduce beetle activity
- Remove and properly dispose of dead oak wood to prevent spreading
Action Step: Call a professional right away if you notice sudden browning in oak leaves. Waiting even a few days can make the difference between saving or losing your tree.
2. Anthracnose
What it is:
Anthracnose is a fungal disease that thrives in Houston’s humid weather. It commonly affects sycamore, oak, ash and dogwood trees.
How to spot it:
- Brown or black irregular spots on leaves
- Leaves curling or becoming distorted
- Branches with sunken areas (cankers)
- Leaves dropping early in the season
Why it’s dangerous:
Repeated infections weaken it over time while anthracnose usually won’t kill a tree which makes it easier for other pests and diseases to attack.
Treatment & Prevention:
- Rake and dispose of fallen leaves, since the fungus survives in leaf litter
- Prune infected branches to stop the spread
- Improve airflow by thinning crowded areas of the canopy
- Apply fungicides if the infection is severe and recurring
Action Step: You should keep your yard clean by removing fallen leaves because this simple step can prevent re-infection each year.
3. Root Rot
What it is:
Root Rot is a common problem in Houston because of clay-heavy soil and poor drainage. Fungal organisms in wet soil attack roots which slowly destroy the tree from below.
How to spot it:
- Yellowing leaves even when the tree has enough water
- Stunted or weak growth
- Mushy or soft roots if you dig near the base
- Tree leaning or showing poor anchoring
Why it’s dangerous:
The tree may not be able to recover once roots are badly damaged. In some cases, the tree becomes unstable and poses a safety risk.
Treatment & Prevention:
- Improve drainage before planting new trees
- Water deeply but not too often that’s why you should avoid constant soggy soil
- Use fungicides in early stages of infection
- Remove severely affected trees if they pose a danger
Action Step: Check your yard after heavy rain. You may need to improve soil drainage if water pools around your trees for more than a day.
4. Powdery Mildew
What it is:
Powdery Mildew is a fungal disease that looks like a dusting of flour on leaves. It spreads quickly in shady and damp areas.
How to spot it:
- White or gray powder on leaves and stems
- New leaves coming out twisted or stunted
- Early leaf drop in severe cases
Why it’s dangerous:
It usually does not kill trees but weakens them, reduces growth and makes them more vulnerable to other problems.
Treatment & Prevention:
- Prune branches to improve sunlight and air circulation
- Avoid watering leaves because only water at the base of the tree
- Apply fungicides during early stages of infection
Action Step: You should act fast before it spreads to nearby plants if you see powder on leaves.
5. Bacterial Leaf Scorch
What it is:
This bacterial disease affects oaks, sycamores and elms in Houston. It blocks the flow of water inside the tree which slowly starves it.
How to spot it:
- Leaves turning brown around the edges, resembling “scorching” from heat
- Branch dieback over several seasons
- Entire tree declines slowly over years
Why it’s dangerous:
There is no complete cure for Bacterial Leaf Scorch. Once infected, a tree will slowly decline.
Treatment & Prevention:
- Injections from a professional can slow the disease
- Regular watering and proper fertilization help reduce stress
- Remove and replace badly infected trees with resistant species
Action Step: You should call an arborist to confirm If you see scorched-looking leaves every summer, no matter if it is a bacterial disease or heat stress.
Tips to Protect Your Trees in Houston
Keeping your trees healthy is the best defense against diseases. A strong tree can fight off many problems on its own while a weak or stressed tree becomes an easy target for infections and pests. Here are some expanded tips that every Houston homeowner should follow:
1. Schedule Regular Inspections
Trees also benefit from regular health inspections just like people need yearly check-ups with a doctor. Certified arborists are trained to notice early warning signs that most homeowners might miss. They can check for symptoms like unusual leaf drop, fungal growth, cracks in the bark or root damage. Early detection is key which catching a problem when it starts can save the tree while waiting too long might mean losing it.
Action Step: You should schedule at least one professional tree inspection each year which ideally in spring or fall when growth changes are easier to notice.
2. Avoid Unnecessary Pruning
Over-pruning or pruning at the wrong time can put your tree under stress while trimming trees is important for shaping and removing deadwood. Open wounds from pruning can become entry points for fungi and bacteria in Houston’s warm and humid climate. This is especially risky during late spring and summer when diseases spread faster.
Action Step: Only prune when it is necessary for safety or tree health and try to do it during cooler months. Always use sharp and sanitized tools to reduce the chance of infection.
3. Keep Trees Healthy With Proper Care
A healthy tree naturally resists many pests and diseases. That means your main goal as a homeowner should be to reduce stress and provide good growing conditions. Trees in Houston often face challenges like compacted soil, drought or flooding after storms. You give your trees the strength to fight off problems by watering correctly, adding mulch around the base (but not against the trunk) and fertilizing when needed.
Action Step: Water deeply once or twice a week during dry spells which keep 2–4 inches of mulch around the base and test soil every few years to see if fertilization is needed.
4. Act Quickly if You Notice Symptoms
Tree diseases spread fast, and waiting too long can make treatment impossible. Don’t ignore them if you notice unusual symptoms like leaves turning brown in midsummer, powdery spots, peeling bark or a sudden lean. Even small issues may point to bigger problems underground or inside the tree. Quick action could save the tree and prevent the disease from spreading to others in your yard.
Action Step: Take clear photos of the problem and contact a local arborist right away. The earlier you get expert advice then the more treatment options you will have.
You can protect your trees from many common diseases in Houston by following these simple but effective steps. Prevention is always easier (and cheaper) than removal and replacement.
FAQs About Tree Diseases in Houston
Yes, diseases like Oak Wilt and Root Rot can spread underground or through insects. That’s why quick action is important.
Minor issues can sometimes be handled with pruning or fungicides but serious problems like Oak Wilt require professional treatment.
At least once a year. Twice a year is better for older or high-value trees.
Oaks, sycamores and elms are most vulnerable but any tree can get sick under stress.
Not always. Some trees can be saved with treatment. Removal is the safest option but if the tree is unstable or beyond recovery.
Conclusion
Tree diseases are a serious threat in Houston and most problems can be managed but with the right knowledge and quick action. You can protect your landscape for years to come by watching for early warning signs which give your trees proper care and working with certified arborists.
At The Tree Pros Houston, we specialize in diagnosing and treating tree diseases across the Houston area. Our team uses safe, effective treatments to restore tree health and prevent further damage from Oak Wilt to Root Rot.
Don’t wait and call The Tree Pros Houston today for expert tree care if you notice unusual leaf drop, browning or decline in your trees.